Hand brake for railway cars



Feb. 9, 1954 F. E. BRETZ, JR 2,668,457

HAND BRAKE FOR RAILWAY CARS Filed Aug. 5. 1950 2 Sheets-Sheet 1 IN VEN TOR.

Feb. 9, 1954 BRETZ, JR 2,668,457

HAND BRAKE FOR RAILWAY CARS Filed Aug. 5. 1950 2 Sheets-Sheet 2 INVENTOR.

70726 Eff/6%, Jk

Patented Feb. 9, 1954 H'AND :BR'AKE FOR RAILWAY CARS; Fifihk"EfBftzf m Oak Park; Ill;, assi,g'n0r -to Ajaxeieblis olidated Company," Chicago, I112," 'a" corporation "of Illinois ApplicatiomAugust 5, 1950;:Serial Not1773041;

8G'lai-msr (CL' 74 505).

This. invention. relates, generally, to brakes, and "it has particular relation torhandbra-kes :forv railway ,carsr I Among the-obj e'cts' of this invention 1 are: To, provide for. appUingNthe-brakes. of .a railway, car b'yrrturning ra-member, v.such asa hand. .wheel, in one direction, andf for relezzsing-athebrakes by. applying-M torque togturn the member tinlthe. op:- posite direction-g toaccom'pli's'h' r, this -b'y interposingma. friction clutch between. the member or handfwheel and a drumon which a. chain con-v n'ectd to the brake riggix igjis'v rwou nd ;l.to operate the fficti onrclutcli cooperating, cam sure faces; .topositionhthecamsurfaces so that awide range; of angles of-iincli'nation can. be employed whereb-yi thereis a widelrange in the torque .re= quired ta rotate. the hand wheellto apply and. rela'sel-the b'rakes';av to employ, ,aafioatingr cam pia'tbetween the camsurfaces andTa'clutchfacefoi' developing;andicontiollihg.thelfriction connection between th'ephand "wheel and the chain winding; drum; to place. the lclutch} face. on a. ratchet wheel and arrange for preventing rota-c tion' A thereof 1 one direction; and l to position the. "friction (cln'tch' mechahis'm between the ratchet wheel and th pifiin which drives .the ma ""gearwheel attached to the chainiwinding drum;

Thisfinirenti'on is "disclosed iii the embodiment thereof shown 'in the accompanying. drawings; and it comprises the features of construction; combination" ofelementsiarid arrangement of parts Whichwill be" exemplifid thlconstrucetion hereinafter setforth'f'and the iscoperofl the application of which 'W'l'lI fb'eifidiatdfin theuap! pendedclainis;

For a more complete,understandings oiQth'e Iia'ture and'"scope" off this invention, reference may be-Had to thefbllowihg' dtaildldeseri p trontaken" together" with? the accompanying drawings; in-which:

Firm-e1} is aview irrfront:erevatiomiatia. .reduced scaieror*a -handiaraiiemecliamsm in which. the-"presentinvention is embodied; ,the t hand; wheel being'ibro'kenf'awayiii, order to illustrate thedetails of 7 construction" of lthecasingand. of. th'"trip "handle";

Figure 2 is a view,,at an enlarged.scale,,pantly in side' eivation and 'pjartlyifi section s'liowing; cee'rtairi'" of the "dtails--'of construction of; the brake mechanism; thefhandf wheellagain' being strewn partially in order not to obscure certain details of construction;

Figure.3 is a-longitudinal-sectional.viewitaken generally along"; the ;.line1-- 3 3 ofJFigure 2,. the. pawl and trip handle-being omitted;-

Figure 4 is...a.viewiat an enlargediscaletaken alongthe line 4-4 of FigureB .and look-main the direction :of .th'evarrows showing the. pinion Land the reenti'ant-T camming, ,s urfaces thereon Figure 5 is a detail'sectionafview, at Janeenlarged scale, taken alonghthe. line. 5A.5 of Figure3' andlook'ingin the cdirectiontof Zthearrows;

Figure 7 6 I is r a detaillsectional lview, at. an enlargedscal, .takengeneralYy; along. ,the.line=6.-6 offFi gni-te 3.and lookingIin-the direction of the arrows; and i Figure 7" is a View, in...side. elevation, of the pinion and cam plate .inspaced 'apart' relationship with the. respectii'zecamming, surfaces in alignment.

Referring now particularly to Figure 1' of the. drawings, ,it i will ,be ob'servedthat; the. reference character It dsignatea. generally, a hand brake mechanism in which the present invention is embodied. The. handfbraker mechanism. i0 includes a rcase shownig-enerally at. II, .wliich comprises a cover ,l2"having,an' outwardly extending" flange 13 that ov erliesJa back plate. It; Figuret3I,-;whic1iencloses-the rear side ofthe cover? 'I 2: The flange I 3? and 'underlying portion of'theba'ck plate M'fareproviddffor mounting: theihand" brake lm'echanism I [L flatwise against the side or endT' of "a railway carv as 4 willv be unederstood' readily. 7 A2 hand'wheel'. [Sis carried by-thehandbrake' mechanism I for therpuitpose"'of-applyin h the brakes. In accordance withthe-present invention thev handlwheel, also is positively. operate'dhb'ythe. brakeman for rel'easingtliebrakes: Also mounted on the fronfisideof thecover I 2 isa trip handle I 6: A's will appea-r hereinafter; the trip handle I? can bet: omitted Connection to" the brake rigging of al-railway car is provided by means ofa chainill.

As: illustratedz nmrefl clearly in" Figure- 3', v the chain: I I is ;secured=byra pinrl 95170181 chainiwin'd ing; 2B nthat iserotatabl y mountedlabout a stationary shait 2.4ywhichiisimounted atits; ends on fltheecoveri l 2 and back plate: I 4: respectively; Formed. integrally with theme-ham [Winding .drum ZED-is a main geanwheelfitwhich hasz geari teeth 23" on its periphery, ,thatL-m-esh with gear; teeth 24of Ia pinionxth'at is showngenerally; atv25r-and is. rotatab'ljri and noneslidabl-y mounted: on" a pinion bearing portion za ofia, ha wheel shaft thatLis shown, generally at. 21., It,wiil be: ob.-: served that the axis of rotation of the hand 3 wheel shaft 21 is parallel to the axis of rotation of the chain winding drum 2!! and of the main gear wheel 22. The hand wheel shaft 2? is mounted at one end on the cover 12 by a bearing casting 28. At its other end the shaft 2i is journaled in a bearing bushing 25 that is carried by an inturned flange 35 of the back plate l i. Near this end of the shaft 2'! a split ring Si is located in a suitable annular groove to prevent endwise movement of the pinion 25. The split ring 3| is held in place by a bearing sleeve 32 that has a press fit with the shaft 21' and itself is journaled in the bearing bushing 26.

In accordance with this invention the hand wheel I5 is connected to the chain winding drum 2!! by means of a friction clutch which is indicated, generally, at 35. As will appear hereinafter, the construction of the friction clutch 35 is such that a positive rotation of the hand wheel I5 is required not only for applying the brakes but also for releasing them.

As a part of the friction clutch 35 a ratchet wheel 36 is employed which is rotatably mounted on the shaft 21 by a bearing bushing 31. The bearing bushing 31 extends over a circular ratchet wheel bearing portion 38 of the shaft 2'5 so that, except as hereinafter provided, the ratchet wheel 36 is freely rotatable on the shaft 21.

The ratchet wheel 36 has ratchet teeth 39 at its periphery with which a ratchet pawl 49, Figure 2, cooperates to prevent reverse rotation. It will be understood that other equivalent means can be employed in lieu of the ratchet teeth 33 and ratchet pawl 43 for preventing reverse rotation of the ratchet wheel 36. The ratchet pawl 40 is pivoted at 4| and is arranged to swing in a clockwise direction so that it is always biased toward the ratchet wheel 36. In some instances it may be desirable to force the ratchet pawl fit to- Ward the ratchet wheel 36. For this purpose a hold down arm 42 can be used and arranged to bear against the rear side of the ratchet pawl as. The arm 42 is carried by a hold down shaft d3 which is journaled in the cover I2 and back plate M as illustrated more clearly in Figure 3. The shaft 43 has a shank 44 at its forward end for receiving the trip handle I6. An arm 45, formed integrally with the shaft 43, bears against the underside of the cover I2 and prevents outward endwise movement of the shaft 43. As described hereinbefore, the hold down arm 42, shaft 33, and trip handle it can be omitted since their only function is to assist the biasing action applied to the ratchet pawl 46 for holding it in engagement with the ratchet wheel 36.

As shown in Figure 3 a collar 58 is formed integrally with the shaft 27 and serves to prevent endwise movement of the bearing bushing 3i and thereby endwise movement of the ratchet wheel 36. As here shown, the ratchet wheel 36 has a flat surface or clutch fac 49 on its left hand side with which an annular friction plate 56 engages. The friction plate 50 is formed of material that is used for facing friction clutches or the like. The other side of the friction plate 56 bears against a flat surface or clutch face 5i formed on the right hand end of a floating cam plate 52. The cam plate 52 is slidably and non-rotatably mounted on the shaft 21. For this purpose a cam plate bushing 53, Figure 5, is employed and it is slidable along a non-circular bearing portion 55 of the shaft 21 as here illustrated. The bearing portion 54 includes a flat surface 55 with which the cam plate bushing 53 and floating cam plate 52 conform.

With a view to moving the floating cam plate along the non-circular bearing surface 54 toward the ratchet wheel 36 so as to provide driving engagement therebetween through the annular friction plate 56, protuberant camming surfaces 56, Figure '7, are provided on the side of the floating cam plate opposite the clutch face 5|. These protuberant camming surfaces 56 also are illustrated in Figure 5. Cooperating with the protuberant camming surfaces 56 are reentrant camming surfaces 51, Figures 4 and 7, that are carried by the pinion 25 on the side facing the hand wheel l5. The cooperating camming surfaces 56 and 51 serve to energize the friction clutch 35 in a manner to be described presently.

The shaft 21 includes a hand wheel attaching portion 6| which projects beyond the cover 12, as shown in Figure-3, for receiving the hand wheel l5. A look nut 62, threaded on the outer end of the portion 6|, serves to hold the hand wheel I5 in position.

As pointed out hereinbefore, the floating cam plate 52 is keyed to the shaft 21 so that it is nonrotatable with respect thereto but it is free to move in either axial direction. When it is desired to apply the brakes, the hand wheel 15 is rotated in a clockwise direction as viewed in Figures 1 and 2 of the drawings. When the hand wheel 55 is rotated in this direction to apply the brakes, the camming surfaces 56 on the floating cam plate 52 move slightly relative to the reentrant camming surfaces 51 on the pinion 25 through an extent which depends, in part, on the tension of the chain II. This relative movement tends to separate the floating cam plate 52 from the pinion 25. Since the pinion 25 is prevented from moving to the left by the split ring 31, the only axial movement that can take place is the movement of the floating cam plate 52 to the right toward the ratchet wheel 36. This movement forces the flat surface or clutch face 5! of the floating cam plate 52 into closer engagement with the adjacent surface of the friction plate 50. In turn the opposite face of the friction plate 56 is brought into closer engagement with the flat surface or clutch face 49 of the ratchet wheel 36. Since the ratchet wheel 36 cannot move axially because of the collar 48, the net effect of the movement of the floating cam plate 52 to the right is to place it in better frictional driving engagement with the ratchet wheel 36. In this manner the stresses incident to the operation of the friction clutch 35 are self contained and, as the hand wheel [5 is rotated in the clockwise direction, the tension of the chain I! is applied to the whole unit which, in effect, constitutes a solid connection between the hand wheel l5 and the chain winding drum 20. This direct connection then will take up the slack in the brakes and apply them with the braking force that is required to the extent that the hand wheel 15 is rotated. As the ratchet wheel 36 rotates in th same direction, the ratchet pawl 40 ratchets over the teeth 39 and acts to hold it in any position to which it may be rotated. On cessation of application of torqu to the hand wheel l5, the brakes remain set to the extent indicated.

When it is desired to release the brakes, the hand wheel i5 is rotated in a counterclockwise direction. The ratchet pawl 46 prevents reverse rotation of the ratchet wheel 36 when this takes place. Since the floating cam plate 52 is ro- 7 chain winding drum said cam plate is moved laterally away from said pinion-and toward said ratchet wheel and thereby has driving connection with said clutch face to'rotate the same and simultaneously said chain winding drum is rotated in the winding direction, said camming means also cooperating so that on rotation of said hand wheel in the opposite direction while said pawl holds said ratchet wheel stationary said cam plate is moved laterally away from said ratchet wheel and clutch face and toward said pinion thereby permitting the latter to turn under the infiuenceof said unwinding torque and effect a corresponding release of the brakes.

5. In a hand brake mechanism the combination with a rotary chain winding drum and a main gear wheel of: a hand wheel shaft mounted for rotation about an axis parallel to the axis of rotation of said chain winding drum and main gear wheel, said hand wheel shaft having a pinion bearing portion at one end, a non-circular hearing portion adjacent said pinion bearing portion, a ratchet wheel bearing portion adjacent said non-circular bearing portion, and a hand wheel attaching portion at the other end; a hand wheel fast on said hand wheel attaching portion, a pinion rotatably mounted on said pinion bearing surface and having at least one reentrant camming surface on the side facing said hand wheel, a floating cam plate slidably mounted on said non-circular bearing portion and having a protuberant camming surface on one side engaging said reentrant camming surface, a ratchet wheel rotatably mounted on said ratchet wheel bearing portion and having a clutch face arranged to have frictional driving connection with the other side of said cam plate, means on said hand wheel shaft preventing movement of said ratchet wheel away from said pinion, and a pawl cooperating with said ratchet wheel to prevent reverse rotation thereof, said camming surfaces cooperating so that on rotation of said hand wheel in one direction with an unwinding torque applied to said chain winding drum said cam plate is moved laterally away from said pinion and toward said ratchet wheel and thereby has driving connection with said clutch face to rotate the same and simultaneously said chain winding drum is rotated in the winding direction,

said camming surfaces also cooperating so that on rotation of said hand wheel in the opposite direction while said pawl holds said ratchet wheel stationary said cam plate is moved laterally away from said ratchet wheel and toward said pinion thereby permitting the latter to turn under the influence of said unwinding torque and effect a wheel fast on'said hand wheel attaching portion, a pinion rotatably mounted on said pinion hearing surface and having at least one reentrant camming surface on the side facing said hand wheel, a floating cam plate slidably mounted on said non-circular bearing portion and having a lprotuberant camming surface engaging said reentrant camming surface, a ratchet wheel rotatably mounted on said ratchet wheel bearing portion, means on said hand wheel shaft preventing movement of said ratchet wheel away from said pinion, a friction plate between said cam plate and said ratchet wheel, and a pawl cooperating with said ratchet wheel to prevent reverse rotation thereof, said camming surfaces cooperating so that on rotation of said hand wheel in one direction with an unwinding torque applied to said chain winding drum said cam plate is moved laterally away from said pinion and toward said ratchet wheel and thereby has driving connection with the latter through said friction plate to rotate the same and simultaneously said chain winding drum is rotated in the winding direction, said camming surfaces also cooperating so that on rotation of said hand wheel in the opposite direction while said pawl holds said ratchet wheel stationary said cam plate is moved laterally away from said ratchet wheel and toward said pinion thereby permit ting the latter to turn under the influence of said unwinding torque and effect a corresponding re lease of the brakes.

7, In a hand brake mechanism, the combination with a rotary chain winding drum and a main gear wheel of: a hand wheel shaft mounted for rotation about an axis parallel to the axis of rotation of said chain winding drum and main gear Wheel, said hand wheel shaft having a pinion bearing portion at one end, a non-circular bearing portion adjacent said pinion bearing portion, a ratchet wheel bearing portion adjacent said non-circular bearing portion, a collar integral with said shaft adjacent said ratchet wheel bearing portion, and a hand wheel attaching portion at the other end; a hand wheel fast on said hand wheel attaching portion, a pinion rotatably mounted on said pinion bearing portion and having at least one reentrant camming surface on the side facing said hand wheel, a floating cam plate slidably mounted on said noncircular bearing portion and having a protuberant camming surface engaging said reentrant camming surface, a ratchet wheel rotatably mounted on said ratchet wheel bearing portion and held against endwise movement along said hand wheel shaft by said collar thereon, a friction plate between said cam plate and said ratchet wheel, and a pawl cooperating with said ratchet wheel to prevent reverse rotation thereof, said camming surfaces cooperating so that on rotation of said hand wheel in one direction with an unwinding torque applied to said chain winding drum said cam plate is moved laterally away from said pinion and toward said ratchet wheel and thereby has driving connection with the latter through said friction plate to rotate the same and simultaneously said chain winding drum is rotated in the winding direction, said camming surfaces also cooperating so that on rotation of said hand wheel in the opposite direction while said pawl holds said ratchet wheel stationary said cam plate is moved laterally away from said ratchet wheel and toward said pinion thereby permitting the latter to turn under the influence of said unwinding torque and effect a corresponding release of the brakes.

8. In a hand brake mechanism, the combination with a rotary chain winding drum and a main gear wheel of: a hand wheel shaft mounted for rotation about an axis parallel to the axis of rotation of said chain winding drum and main gear wheel, said hand wheel shaft having a pinion bearing portion at one end, a non-circular bearing portion adjacent said pinion bearing portion, a ratchet wheel bearing portion adjacent said non-circular bearing portion, a collar integral with said shaft adjacent said ratchet wheel bearing portion, and a hand wheel attaching portion at the other end; a hand wheel fast on said hand wheel attaching portion, a pinion rotatably mounted on said pinion bearing portion and having at least one reentrant camming surface on the side facing said hand wheel, a floating cam plate slidably mounted on said non-circular bearing portion and having a protuberant camming surface engaging said reentrant camming surface, a ratchet wheel rotatably mounted on said ratchet wheel bearing portion and held against endwise movement along said hand wheel shaft by said collar thereon, a friction plate between said cam plate and said ratchet wheel, a pawl cooperating with said ratchet wheel to prevent reverse rotation thereof, a hold down shaft mounted for rotation about an axis parallel to the axis of rotation of said hand wheel shaft, a handle fast on said hold down shaft, and a hold down arm on said hold down shaft for engaging said pawl and holding it in engagement with the teeth of said ratchet wheel, said camming surfaces cooperating so that on rotation of said hand wheel in one direction with an unwinding torque applied to 10 said chain winding drum said cam plate is moved laterally away from said pinion and toward said ratchet wheel and thereby has driving connection with the latter through said friction plate to rotate the same and simultaneously said chain winding drum is rotated in the winding direction, said camming surfaces also cooperating so that on rotation of said hand wheel in the opposite direction while said pawl holds said ratchet wheel stationary said cam plate is moved laterally away from said ratchet wheel and toward said pinion thereby permitting the latter to turn under the influence of said unwinding torque and effect a corresponding release of the brakes.

FRANK E. BRE'IZ, JR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,166,201 Van Cleave July 18, 1939 2,189,978 Dyke Feb. 13, 1940 2,267,037 Mersereau Dec. 23, 1941 2,268,228 Van Cleave Dec. 30, 1941 2,280,180 Van Cleave Apr. 21, 1942 2,282,736 Mersereau May 12, 1942 2,299,402 Mersereau Oct. 20, 1942 2,310,135 Van Cleave Feb. 2, 1943 2,416,251 Camp Feb. 18, 1947 

